Process of making formates.



UNITD STATES PATENT OFFICE.

GEORG BREDIG, OF KARLSRUHE, GERMANY, ASS IGNOR T0 FIRM 0F RUDOLPH KOEPP8c 00., OF OESTRICH-ON-THE-RHINE, GERMANY, (A GERMAN SOCIETY.)

PROCESS OF MAKING FORMATES.

No Drawing.

To all whom it may concern:

lie it known that I. (inonu BREDIG, a subject of the German Emperor, andresident of Karlsruhe, Baden, Germany, have invented certain new anduseful Improvements in the Process of Haking Formates, of which thefollowing is a specification.

.My invention relates to a process of obtaining formic acid compoundsfrom carbonic acid or its compounds by reduction.

I am aware that it is old to obtain formates by subjecting bicarbonatesto the reducing action of hydrogen in static aascemiz' under ordinarypressure, but such processes requiring the use of hydrogen in statunasecml are-seldom practicable on a manufacturing scale. Incontradistinction to this old method I use ordinary hydrogen and I allowit to act upon a CO -containing substance suclras carbon dioxid,carbonic acid or a carbonic acid salt in the presence of a' catalyst. ahigh pressure being maintained during the reaction. If carbon dioxiditself is used, some substance capable of combining formic acid shouldbe present, such as a salt of a diliicultly soluble acid or of an acidwhich is weaker than vformic acid.

The possibility of obtaining formic acid from carbonic acid by aid ofordinary hydrogen was the more improbable for the reason that others hadpreviously worked along these lines, but had failed to get anysatisfactory results. M. Kleinstiick (Zez'tschm'ft ffir nngcwamlze(Uremic 23 (1910) page 1106) treated bicarbonate of alkali in thepresence of palladium alumina with hydrogen gas under ordinary pressureand thought, it is true, that he produced formic acid. However, thequantities developed in the circumstances stated by him were obviously.so small as to prevent him from determining with certainty whether, infact, formic acid or formaldehyde was obtained. He speaks of formic acidor formaldehyde, but all he was able to prove with the aid ofalmnoniacal silver solution was the presence of reducing agents.

According to my invention, however, fol-mates are obtained on acommercial scale by causing ordinary hydrogen to act, under a pressuresubstantially greater than atmospheric pressure and in presence ofcatalytic agents. upon carbonic acid, either in its gaseous state or inthe form of a bicarbonate. If carbonic acid gas is used, a substanceSpecification of Letters Patent.

Application filed December 4, 1914.

Patented Nov. 14, 1916.

Serial No. 875,466.

capable of binding the formic acid forming should be present. Instead ofthe ordinary carbonic acid gas, which can be obtained nowadays at a lowprice, a mixture of carbonic acid gas with other gases, such as forinstance hydrogen, may be used.

Example I: 200 com. of a 5 per cent. solution of bicarbonate of potashand 1.5 g. palladium-black are stirred vigorously with lrvdrogen gas ata temperature of 70 degr. C. and a pressure of atmospheres. 75 per cent.of the bicarbonate present is converted into formate.

Example II: Carbonate of calcium is subjected at 70 degr. C. in thepresence of water and palladium-black to the simultaneous action ofcarbonic acid gas of 20 atmospheres and hydrogen gas of 50 atmospheres.Vithin a few hours Vigorous stirring the carbonate is transformed intoformate.

Example III: 200 com. of a 5 per cent. solution'of borax and 1.5 g.palladium-black are subjected at 70 degr. C. to the simultaneous actionof hydrogen gas of 30 atmospheres and carbonic acid gas of 30atmospheres. After eight hours stirring about 20 per cent. of the boraxis converted into forma-te.

I claim: v

1. The process of making formates which comprises treating a CO-containing substance with ordinary hydrogen gas under.

a pressuresubstantially greater than atmospheric pressure in thepresence of a catalyst.

2. The process of making formates which comprises treating carbon dioxidand a substance capable of binding formic acid-with ordinary hydrogengas under a pressure substantially greater-than atmospheric pressure inthe presence of water and a catalyst.

3. The process of making formates which comprises treating carbon dioxidand a salt of an acid which is weaker than formic acid with ordinaryhydrogen gas under a pressure substantially greater than atmosphericpressure in the presence of water and a catalyst.

4. The process of making form-ates which comprises treating carbondioxid and a carbonate with ordinary hydrogen gas under a pressuresubstantially greater than atmospheric pressure in the presence of waterand a catalyst.

5. The process of making for-mates which comprises treating a substancecapable during the reaction of'iyielding both carbon dloxid and acompound capable of binding formic acid, with ordinary hydrogen gasunder a pressure substantially greater than stance with ordinaryhydrogen gas under a pressure substantially greater than atmosphericpressure in thepresence of a catalytic metal of the platinum group.

8. The process of making formates which comprises treating carbon dioXidand a salt of an acid which is weaker than formic acid with ordinaryhydrogen gas under a pressure substantially greater than atmosphericpressure in the presence of water and palladium black.

9. The process of making formates which comprises treating a CO-containing substance with ordinary hydrogen gas under a pressure offrom 30 to 60 atmospheres in the presence of a catalyst.

10. The process of making formates which comprises treating carbondioxid and a substance capable of binding formic acid with ordinaryhydrogen gas under a pressure of from 30 to 60 atmospheres in thepresence of water and a catalyst.

11. The process of making formates which comprises treating a Co-containing substance with ordinary hydrogen gas under a pressure offrom 30 to 60 atmospheres in the presence of a catalytic metal of theplatinum group.

12. The process of making formates which comprises treating carbondioxid and a substance capable of binding formic acid with ordinaryhydrogen gas under a pressure of from 30 to 60 atmospheres in thepresence of water and a catalytic metal of the platinum group.

13. The process of making formates which comprises treating abicarbonate with ordinary hydrogen gas under a pressure of more thanthirty atmospheres in the presence of water and a catalyst.

14. The process of making formates which comprises treating at atemperature of about 70 C. a cO -containing substance with ordinaryhydrogen gas under a pressure substantially greater than atmosphericpressure in the presence of a catalyst.

15. The process of making formates which comprises treating at atemperature of about 70 C. carbon dioxid and a salt of an acid which isweaker than formic acid with ordinary hydrogen gas under a pressuresubstantially greater than atmospheric pressure in the presence of waterand a catalyst.

16. The process of making formates which comprises treating at atemperature of about 70 C. a (O -containing substance with ordinaryhydrogen gas under a pressure of from 30 to 60 atmospheres in thepresence of a catalyst.

17. The process of making formates which comprises treating at atemperature of about 70 C. carbon di'oxid and a substance capable ofbinding formic acid with ordinary hydrogen gas under a pressure of from30 to (30 atmospheres 1n the presence of water and a metal of theplatinum group.

Intestimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

GEORG BREDIG.

Witnesses:

H. MERLE COCHRAN, MATHILDE NARRAWAY.

